<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>盒子阴影</title>
    <style>
        div{
            width: 200px;
            height: 200px;
            background: yellow;
            margin: 0 auto;
            box-shadow: 10px 10px 10px 10px red inset;
            /* box-shadow: 10px 10px 10px red,  -10px -10px 10px gold; */
        }
    </style>
</head>
<body>
    <div></div>
</body>
</html>